I have a 2001 suburban with 140K, The fuel gauge will drop suddenly as if it is getting no power and the check fuel light will come on. This happens about every 10 minutes and last for 20 - 70 seconds. When it comes back on, it usually reads correct but not always. Car runs fine while this is happening. Help!
Relax, it’s a 9 1/2 year old car and this is a minor irritation. Unless it quits working altogether I wouldn’t spend the money to fix it.
My Best Guess Is That The Fuel Level Sender (In The Gas Tank) Has Gone Bad. If There Is No Access Panel Above The Fuel Pump / Gauge Module Then The Tank Has To Be Dropped Down To Access It.
Many (most ?) of these GM senders are available separately, without having to replace the fuel pump, too.
Contact an independent mechanic / shop. There is a procedure for testing the sensor (sender). Although not simple and easy, replacement may not be too bad, money-wise. Most shops have experience replacing these. See if your shop has done them.
Go in with an almost empty tank if possible. Don’t know how much gas is in there ? Do you know your approximate range ? Then fill it and drive just short of your range and take it into the shop.
CSA
Like CSA stated, the problem may be with the level sensor, possibly the contacts are dirty. Some folks have cleared this kind of trouble by adding a product from Chevron called Techron to the fuel at fill up which cleans the fuel system. It may take a couple of tank fills to work but then, it may not work. If it does work you will save a lot of money over having the sensor replaced. I would say it is worth a try at least.
Cougar, It Certainly Is Worth A Try, Even Suggested By GM. However, Usually The Little Metal “Fingers” On The Wiper Part Of The Sesor Disintegrate (Dissolve) Because Of Reaction To The Sulfur In Gasoline.
I’ve used Techron and after that I’ve seen what the wipers look like when I replaced a level sensor. Some of the metal is gone.
CSA
This has been happening on my 2001 Silverado. It is the contacts inside the fuel sender that have become worn and/or gunked-up/and/or corroded. I have tried Techron and Seafoam with no success. Supposedly GM sells a gas additive cleaner for this problem, but I have not tried it. Replacement fuel senders available over the Internet advertise gold contacts that won’t corrode, but I have not tried them either. A replacement sending unit will cost anywhere from $125 to $200 if I remember correctly, plus the labor to put it in (droping the gas tank). So far it is only a problem for mee when the tank is full, so I haven’t bothered to get it fixed. If the Low Fuel light was on more often, I would be annoyed enough to get it fixed, but we are not there yet.